Not your typical fret buzz...

[Dave]

I have been fretting (sorry! troubling) over a particularly annoying back buzz on a Guild dread I picked up off eBay about a year ago, and thought I would run it by folks here for some additional insight...

Upon it’s arrival, I noticed a 2-3" separation of the fretboard from the neck near the nut, which I had repaired. The frets were also leveled and crowned at the time of the repair. The buzz was present before the repair... I was hoping the repair and fret work would eliminate it,  but it is still there still there.

The back buzz occurs ONLY when I capo on the second fret, and strum (with some power) any chord which frets the 1^st AND 6^th strings at the 5^th fret [for example, an open or barred G, or any barred C form (C, Cm, etc)]. You can also generate the buzz by putting capos on both 2^nd and 5^th frets, and playing the 1st string (high e). With a little experimentation, I discovered that the buzz is a sympathetic back buzz of the 6^th string between the capo on the 2^nd fret and my finger fretting on the 5^th (or between the two capos), which is induced by vibration of the 1^st string fretted on 5 (A). I am know this is the root of the buzz, since when it occurs with the open G form, I can wrap my thumb around and mute the buzz by touching the 6^th string between the capo (on 2) and my fretting finger (on 5), or if using the two capos, I can mute it by touching the string between the capos.

It appears the short length of 6^th string between the capo on 2 and fretting finger on 5 (the string between 2^nd and 4^th frets?) vibrates at an octave of the A (at least it sounds pretty close to my ear), and thus is induced to sympathetically vibrate when the 1^st string A is strummed or plucked hard ... but it makes light contact with the 3^rd fret, and buzzes.

The buzz occurs only when capoed at 2 and then fretted at 5, ruling out the nut slot depth as the problem. Likewise, since the back buzz is between the capo at the 2^nd fret and finger or capo at 5^th fret, action and saddle height are not the issue. I have used a straight edge to check/rock the frets, and the none of frets 1-5 seem to be high or low (in all other respects, the frets are in great condition after the level and crown).

I am able to minimize (but not completely eliminate) the buzz by loosening the truss, increasing the neck relief to ~0.009" or more (fretted at 1 and 14 and measured at 8)... higher than I would like it to be. I have tried two different strings (I play John Pearse PB lights, but have also tried JP 80/20s lights)... but have wondered if the extra mass of a medium gauge 6^th string (maybe a bluegrass set) might help reduce the sympathetic vibration, but haven’t tried that expt yet.

This guitar has become my favorite player since I got it, but I play a large part of my repertoire capoed at 2 to match my voice... making the buzz particularly annoying. If anyone has other ideas of what might be happening, and how the buzz might be eliminated, I would really appreciate hearing them.

[Paul Verticchio]

Whatever path you choose, Dave, it'll be worth it to get another Guild acoustic singing to the world..with a clear voice :)

One more thing just occurred to me: the frets may need to be re-crowned to a rounder profile. If they were crowned with a school bus shape, the minute extra fret stock could be the sole cause of the issue.

Perhaps the tech that did the level/crown/polish for you may simply need to do just a bit more rounding. Personally, I'd look for a better tech. This issue should have been resolved before the instrument was returned to you.

A low 3rd fret? Those are the things that a level etc are supposed to eliminate, not cause. Either way, I'd ask for a price adjustment or a free repetition of the original work. If neither is offered, again, I'd look for a different tech.

Things keep popping in my head: Guild's are well known for having their headstock plates come loose. This occurs at the edges of the overlay but I've also seen them develop bubbles right in the middle of the headstock. That factor could assuredly cause sympathetic resonances. It's just something to look for.

re: the fretrocker; I'm one of the guys that doesn't use one. I approach fret & FB work a system. We've had several fretrocker threads on this forum. You might want to search the archives for info &/or tips.  IMPO, fighting a single fret, especially a low one, is a futile act.  Look especially for comments by Hesh Breakstone & Rusty Vance.

Best of luck on the outcome & have a great weekend our friend :).